United States sprinter Justin Gatlin, who has twice been banned from the sport for separate doping offences, has been handed a new sponsorship deal with Nike.

The 33-year-old will wear kit provided by the Oregon-based company in the lead up to the World Athletics Championships in Beijing having worn kit made by Chinese company Xtep since his return from his second ban in 2010.

Gatlin ran four of the five fastest 100m times in 2014 and is among the favourites to win gold at the major championships in August; however Nike has come under fire for the move which sees it reward a disgraced drugs cheat.

Women's marathon record holder Paula Radcliffe, who is also backed by Nike, wrote on Twitter: "I am very disappointed to hear this news.

"I don't believe it truly reflects the core values of the Nike that I am proud to represent nor the integrity and ideals of the people there that I work with on a daily basis."

The two-time world champion in Helsinki in 2005 was banned for two years after testing positive for amphetamines in 2001 and then reprimanded for a second time in 2006 after taking testosterone.

He returned for the London 2012 Olympic Games, winning bronze behind Usain Bolt and Yohan Blake in the 100m final, finishing ahead of fellow-disgraced American Tyson Gay, who will not be backed by Nike.

"We have recently signed a contract with Justin," said Nike North America communications vice-president Charlie Brooks.

"Earlier in his career, Justin served the ban that was imposed on him and has been competing again for almost five years. We have no plans to sign a contract with Tyson Gay."