David Weir says he feels like he has been "stabbed in the back" following an unsuccessful Paralympic Games in Rio.
The 37-year-old, who won four gold medals in London four years ago, returns from Brazil empty-handed after crashing in Sunday's marathon.
Speaking to BBC Radio 5 live, Weir refused to explain his unhappiness.
"I always praise every athlete to put on a British vest but sometimes I feel like I've been stabbed in the back," said the Londoner.
Weir, who was born with a spinal cord transection that left him unable to use his legs, will retire after the London Marathon in 2017.
Baroness Tanni Grey-Thompson, who won 11 Paralympic gold medals in wheelchair racing, said Weir has felt isolated from the rest of the British team.
"He's said it's nothing to do with training and it's nothing to do with his family," said Grey-Thompson.
"It sounds like the village set-up wasn't quite what he wanted. He talks about feeling isolated. He feels separate from the rest of the team."
She added: "As an ex-athlete, it's really hard to hear him say he feels 'stabbed in the back'. What the team need to do is listen to Dave and listen to his concerns, because if an athlete of his level is not happy, you have to listen."
Speaking before the closing ceremony, Weir said: "We need to click as a team. I know it's an individual event, but there needs to be no big egos within the team.
"We need to all work together, like the US team, the Aussie team. I just want to see Britain win a lot of medals in wheelchair racing.
"I'm never jealous of anyone and if somebody beats me I'm happy, as long as they are competing for a medal. I want the team to do well and I want wheelchair racing to be successful all around the country."
GB's wheelchair racers won eight medals in Rio.
Hannah Cockroft claimed three golds and team-mate Kare Adenegan took home one silver and two bronze, both in the T34 category.
Toby Gold won silver and Andrew Small bronze in the T33 100m.
Weir missed the birth of his fourth child to compete in Rio and said on Twitter he had "let the country and my team-mates down".
In the women's T54 marathon, American Tatyana McFadden was denied her fifth Paralympic gold medal in Rio by an inch of a wheel as China's Zou Lihong edged home in a thrilling sprint finish.
The first seven women to cross the line all finished within three seconds of each other and it was McFadden's compatriot Amanda McGrory who completed the podium, finishing one hundredth of a second behind McFadden and Lihong.
After the sad news Iran received yesterday of the death of Iranian cyclist Bahman Golbarnezhad, their men's sitting volleyball team won a gold medal, beating Bosnia & Herzegovina 3-1.
And finally, Australia retained their title as wheelchair rugby's Paralympic champions, prevailing 59-58 in hard-fought game with USA.