It is believed that this decision is associated with comments he made about Len McCluskey during the recent election campaign in which Mr Coyne was a contender to become general secretary of Unite. Some statements by Coyne have referred to the purchase of a flat with the help of trade union loans.
There have also claims that Coyne's campaign used Labour party data to contact members to see whether they would back him.
This suspension from his post ought not impact on the leadership election,.
Ballots closed yesterday, with turnout said to be lower than expected at around 12 per cent.
Insiders have described the result as being 'on a knife edge'.
Unite has 1.4 million members, and last year donated £1.5 million to the Labour party.
'The battle to be the union's general secretary is understood to be on a "knife edge," from early sampling of the ballots by both sides.'
Counting is due to be completed tomorrow with the result to be announced next week.