Four-time Olympic champion Sir Mo Farah has announced he and his controversial coach are parting ways.
Alberto Salazar has been accused of breaking anti-doping rules while training athletes at the Nike Oregon Project, where Sir Mo has been coached since 2011.
Salazar is being investigated by the US Anti-Doping Agency and has denied any wrongdoing. Sir Mo has not been accused of any wrongdoing.
The situation was not mentioned in a video the athlete posted on Twitter announcing the split and his impending return to the UK.
The 34-year-old said: "I really miss home, seeing my kids, how happy they were in the summer at the world championships…I'm going to be back there."
Sir Mo will instead work with Gary Lough as he focuses on marathon running, having ended his track career. Lough previously coached women's marathon world record holder Paula Radcliffe.
Sir Mo retired from track racing to concentrate on marathons after winning 10,000m gold and 5,000m silver at the World Championships in London in August.
That month he told reporters: "You can write what you like, I'm a clean athlete and as long as I understand that I sleep well at night."
He had also described the repeated focus on Salazar as like a "broken record".
He added that Salazar had not been at any races with him that season and that he had not decided whether he would use his support as he starts to tackle road racing.
"For the last three or four years I have been pretty much by myself and it didn't make much difference really – I knew what I needed to do," he said.