Jenson Button says Lewis Hamilton acted a "bit weird" when they were teammates at McLaren, after revealing for the first time in his autobiography just how strained their relationship got at times.
In an exclusive extract from his new book 'Life to the Limit' that has appeared in The Daily Telegraph, Button says that there were several flash points in their time together that he found difficult to understand.
The first came at the 2010 Turkish Grand Prix, when Button said he and Hamilton nearly came to blows when he was accused of ignoring team orders.
"Midway through that first season, I was ahead of Lewis in the points," wrote Button. "Did he like being beaten by his teammate? 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 left angry that Button had overtaken him at a time when he thought they were holding position. And rather than check things out with the team, Hamilton confronted Button over it.
"On the podium there was what the media called some 'frosty' body language and a 'muted' celebration. In fact, he came straight out and asked me about it: "Did you pass me against team orders?" said Button.
"He was the winner. Jesus.
"No," I told him, "I did not pass you against orders. I was never told not to pass you.
"That sent him off thinking that the team were taking my side against his, though he never did explain why they would want to do that, given that we were on course for a one–two and, apart from our respective race engineers, nobody in the team would give a flying f*** who came first and who came second.
"It was a bit weird, slightly unnecessary and a little more proof that all was not well behind the smiles."
Button also said that he was far from impressed at the 2012 Belgian Grand Prix, 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 is published this Thursday and is available from all good book stores.