Four-time Olympic champion, Mo Farah and Haile Gebrselassie are involved in a dispute over an alleged theft at a hotel belonging to the Ethiopian athletics great in Addis Ababa.
The Briton said he had money, a watch and two phones taken from his room, and that Gebrselassie did not help him.
“I was just disappointed with Haile,” said 36-year-old Farah.
Gebrselassie, 46, responded by accusing Farah of “blackmail” and “defaming” his reputation and business.
Farah made the claims at the media preview event of Sunday’s London Marathon.
“Just to be honest, it’s Haile who owns the hotel and when you stay for three months in that hotel, it was very disappointing to know that someone who has that hotel and that kind of support couldn’t do nothing,” said Farah, who had been training in Ethiopia.
In a statement, double Olympic 10,000m champion Gebrselassie said he was considering taking legal action against Farah.
He said a text message he received from Farah before the London Marathon news conference was an attempt to “blackmail” him.
Gebrselassie said guests staying at his hotel are asked to declare if they are carrying more than $350 (£271) in cash, so they could be given the option of keeping the money in a safe box or give it to officials for safe-keeping.
He claimed that Farah chose to hold on to his money, which meant his hotel was not legally accountable for it.
Gebrselassie said the alleged theft was reported and that five of the hotel’s employees were investigated but released without charge, adding that police “found nothing on the reported robbery case”.