Jenson Button says Lewis Hamilton acted a "bit weird" during their time as McLaren team-mates, after revealing in his autobiography just how strained their relationship got at times.
In an exclusive extract from his new book 'Life to the Limit', which appeared in The Daily Telegraph, Button said there were several flash points in their time together that he found difficult to understand.
The first came in their first season together during the 2010 Turkish Grand Prix.
"Midway through that first season, I was ahead of Lewis in the points," wrote Button.
"Did he like being beaten by his team-mate? Probably not, but he's a competitor and I'm sure that like me he relished the challenge.
"That's why we do what we do.
"Personally, he was fine with me, but you could just tell he was a little bit peeved. I don't think that I was to his taste, if I'm honest.
"And things took a bit of a turn for the worse in Turkey, when we almost had a collision that led to a minor falling-out between us."
In that race, then leader Hamilton was angry that Button had overtaken him at a time when he thought they were holding position and confronted Button about his actions afterwards.
"On the podium there was what the media called some 'frosty' body language and a 'muted' celebration," Button added.
"In fact, he came straight out and asked me about it: "Did you pass me against team orders?" "He was the winner. Jesus.
""No," I told him, "I did not pass you against orders. I was never told not to pass you."
"It was a bit weird, slightly unnecessary and a little more proof that all was not well behind the smiles."
Button added he had been unimpressed during the 2012 Belgian Grand Prix weekend, when Hamilton tweeted secret telemetry data to show why he had lost out by running a different rear wing design in qualifying.
"Quite what was in his thinking, I couldn't say," said Button.
"Certainly any displeasure he was showing was aimed at the team, not me, but I ended up being collateral damage because you don't make telemetry public. You just don't.
"The screen grab showed the kind of things you work hard to keep hidden from your rivals. I made my feelings known about that.
"The official version was that I was "disappointed". Had I gone with my unofficial reaction it would have made 'WTF' seem very tame indeed.
"But at the same time I knew it wasn't personal. Bit dumb maybe. But not an 'I hate Jenson' thing so much as an 'I'm fed up with McLaren' thing.
"Later in the season, it was officially announced, that Lewis was leaving to partner Nico Rosberg at Mercedes.
"That was a shame for me; I'd enjoyed our rivalry. Off the track, however, he was still being a bit weird."
Life to the Limit by Jenson Button (Blink Publishing) is out this Thursday