Northern Ireland born MP Conor Burns has been sacked from the Government following a complaint of "serious misconduct".
The former trade minister has also had the Tory whip suspended pending an investigation into "allegations of inappropriate behaviour" earlier this week.
The MP for Bournemouth West, who has held the seat since 2010, has said he will co-operate fully with the probe and "looks forward to clearing his name", according to The Sun.
Read more: Arlene Foster to become House of Lords peer 'within days'
A No 10 spokesperson said: "Following a complaint of serious misconduct, the Prime Minister has asked Conor Burns MP to leave the Government with immediate effect.
"The Prime Minister took direct action on being informed of this allegation and is clear that all ministers should maintain the high standards of behaviour - as the public rightly expects."
A spokesman for the Whips' Office said: "We have suspended the whip pending investigation into allegations of inappropriate behaviour earlier this week.
"We take all such allegations extremely seriously. The Prime Minister has been clear that the highest standards in public life must be upheld."
The PA news agency has approached Mr Burns for comment.
READ NEXT:
- UK government's approach to Brexit left us 'all screwed', says unionist former Justice Minister
- Watch: Arlene Foster learns Irish-language roots of Fermanagh childhood home in TV show
- Stormont and councils in Northern Ireland 'exploring options' to save energy in winter
DUP's Jeffrey Donaldson to 'take steps' to oppose council deal on Brexit NI Protocol
For all the latest news, visit the Belfast Live homepage here. To sign up to our FREE newsletters, see here.
