MARTHA KELNER: Justin Gatlin can produce a nightmare scenario for advocates of clean sport by breaking Usain Bolt’s 100metres world record this summer, according to ex-sprinter John Regis.

Switzerland is renowned for being neutral but the country nailed its colours to the mast where drug cheats are concerned by hosting the dirtiest Diamond League race this century.

Next month’s World Championships men’s 100m final is in danger of rivalling the 1988 Olympic final in Seoul as the ‘Dirtiest Race in History’.

Justin Gatlin could win world championships and go undefeated for a second consecutive season but he would still not be ineligible for the sport's athlete of the year award.

American sprinter Justin Gatlin continued his fine form by clocking 9.78 to win the 100 metres at the Herculis Diamond League meet on Friday.

MARTHA KELNER AT THE OLYMPIC STADIUM: Usain Bolt allayed any concerns over his fitness, twice running 100m in 9.87 seconds at the Sainsbury's Anniversary Games.

Usain Bolt celebrated his first serious 100metres win of the season by celebrating in London. Bolt was spotted at swanky west London nightclub Libertines following his 9.87 second win.

On Sunday night the best 100m sprinters in the world will settle down on to their blocks in the iconic Bird’s Nest Stadium in Beijing, the scene of much heroics in the 2008 Olympics.

MATT LAWTON: Seb Coe has said he will feel ‘queasy’ should Justin Gatlin, or any other convicted drugs cheat, win gold at the World Athletics Championships in Beijing.

MARTHA KELNER IN BEIJING: Usain Bolt goes head to head with the two-time drug cheat over 100m and 200m at the World Championships in Beijing this weekend.

Usain Bolt turns 29 on Friday. There might be a modest slice of cake and a rendition of Happy Birthday from his Jamaican team-mates but otherwise the significance of the day will be ignored.

MARTHA KELNER IN BEIJING: The roll call of winners from the first round of the World Championships 100m was almost farcical with four of the seven previously serving drugs bans.

Usain Bolt managed to survive a stuttering start to move into the World Championships 100m final in Beijing, setting up an enticing showdown with Justin Gatlin, who stormed through in his heat.

As Usain Bolt fulfilled his final media duties inside the Bird’s Nest stadium after winning 100m gold, with cleaners tidying around him and, a fan draped draped in the Jamaican flag screamed: ‘Yes Usain Bolt!'

American sprinter Justin Gatlin will refuse to speak to British media and the BBC in the future following 'hurtful attacks' and 'biased views' in reports having won silver in the 100m World Championship final.

Usain Bolt and Justin Gatlin set up the sequel to their world championship sprint showdown on Wednesday, both winning their semifinal heats in the 200 metres.

Justin Gatlin hopes the public will see him as a 'human being' rather than a drugs cheat after the World Championships. Gatlin finished second in the 100m and 200m in Beijing.

CHARLES SALE: Lord Coe’s unparalleled reputation as Britain’s leading sporting statesman is in danger of being tainted by his continued links with Nike.

USA's Justin Gatlin, 34, hopes to become the fastest man in the world, beating out rival sprinter Jamaican Usain Bolt. The New Yorker has been banned from the Olympics twice for doping

The Jamaican was forced to settle for third in his final solo race at the London Stadium on Saturday after being beaten by the USA's Christian Coleman, who claimed silver, and Justin Gatlin, who won the gold.

Bolt claimed all the headlines as the star of a generation took his final bow in an emotional night in the English capital. And his sporting contemporaries paid homage to his career.

Gatlin has rejected the allegations, for which he is considering suing the newspaper, and has sacked Mitchell, who won 4x100m relay gold for the USA in 1992 before being banned in 1998.

EXCLUSIVE - RIATH AL-SAMARRAI: British Athletics will be spared the embarrassment of Justin Gatlin racing at its inaugural Athletics World Cup in London next month.

Jerome Boateng has been fined by Bundesliga giants Bayern Munich after crashing his Mercedes on the motorway while driving back from visiting his ill son.

Bayern Munich goalkeeper Manuel Neuer has taken to Instagram to show off how he is keeping his reflexes sharp during the football shutdown.  

Chelsea have reportedly made the first move in the race to sign Philippe Coutinho this summer. The attacking midfielder joined Barcelona from Liverpool in a deal worth £145m two years ago.

Few players are heading into the summer with their future as uncertain as Barcelona's Philippe Coutinho. With that in mind, Sportsmail assesses his potential landing spots - and where he suits best.

Bayern Munich players will return to training on Monday for the first time since the Bundesliga campaign was suspended. The top flight has been on hold since March 13 due to the coronavirus pandemic.

'Outrageous' transfer fees will become a thing of the past after the coronavirus pandemic, Bayern Munich president Herbert Hainer believes.

Jerome Boateng's year in the Premier League between 2010 and 2011 was one to forget. He failed to earn a first XI place at Manchester City and was often played out of position at right back.

Bayern Munich and Borussia Dortmund are both said to be interested in Antonio Rudiger. Rudiger has reportedly opened contract talks with Chelsea but has been linked with a move away.

The Frenchman has fallen down the pecking order this season under Hansi Flick, having started just seven games under the new manager at the Allianz Arena.

Bayern Munich's pursuit of Leroy Sane has been dealt a serious blow due to the coronavirus crisis, according to reports. The Bundesliga champions are long-term admirers of the Manchester City winger.

The former Chelsea and Bayern Munich star opened up on the couple's health fright, and highlighted that Bernadien had struggled to recover from the virus over a sustained period.

Arsenal were warned against the signings of Shkodran Mustafi and Lucas Perez by their own head of recruitment in 2016, in the same window the club lost Serge Gnaby for just £5million.

UEFA president said he would consider finishing the European competitions behind closed doors but will accept they might have to be cancelled if they were unable to resume by September.

Sagnol, who was working as a scout at Bayern Munich as Varane rose through the ranks at Lens, claimed he got a tip-off about the 18-year-old defender from a friend.

The Moroccan international has developed into one of the most coveted full-backs in Europe after an impressive two-year loan stint at Borussia Dortmund from Real Madrid.

The league's chief Christian Seifert did suggest last week that the current plan is for games to return to all 36 grounds in the top two divisions by the start of May.

PSG's Kylian Mbappe has been ranked as the fastest footballer in the world according to data from French newspaper Le Figaro, beating a lot of other famous speedsters.

Everton are reportedlyinterested in signing Torino's Andrea Belotti this summer, with Manchester United and Napoli also pursuing the striker. 

Bayern have a key relationship with Audi, and the German manufacturers have provided every squad member with a new car since 2002, the year they became a shareholder of the club.

Every now and again - but not often - a player will make the brave decision to move from his current club to their biggest rivals. Here, Sportsmail takes a look at ten transfers between rival clubs.

Matches will continue behind closed doors with a maximum of 322 people in and around stadiums for top-flight Bundesliga matches and 270 for second-tier games.

Frank Lampard inherited the £72million Kepa upon his arrival at Chelsea last summer, but a series of high-profile errors have seen the Spanish stopper come under serious scrutiny.

Bayern Munich midfielder Philippe Coutinho underwent minor surgery on his right ankle on Friday and will start his rehabilitation programme in about two weeks, the German champions said.

Bayern Munich star Alphonso Davies has quickly become one of the clubs most valued assets, but it doesn't mean he didn't have those first-day nerves meeting some of his superstar teammates.

Hasan Salihamidzic confirmed there had been no resolution to contract negotiations with Manuel Neuer, but confirmed the Germany international has been placated after his outburst last week.

The Brazilian is currently on loan at Bayern Munich but has not done enough in the Bundesliga to convince the league leaders to make his move permanent. Chelsea now may not move, either.

Robben ended his playing career last summer and admits that, while he initially didn't miss football, he started to think about possibly playing again.