A lifeboat has been grounded after RNLI crew members were suspended.
The Arbroath lifeboat in Angus has been taken out of service will an investigation takes place.
A lack of available crew members means cover will be provided from Montrose and Broughty Ferry.
An RNLI spokesman said the organisation will not tolerate inappropriate behaviour.
He said: "We are currently undertaking an investigation at Arbroath Lifeboat Station following a complaint about a serious incident.
"We won't be in a position to comment on the details of the incident until the investigation has reached a conclusion."
"However, some crew members have been temporarily stood down while the investigation is being carried out.
"As a result the all-weather lifeboat is currently off service due to the lack of availability of operational crew."
He added: "The RNLI is 100% committed to saving lives at sea and would never consider taking a lifeboat off service unless there was due cause and reason.
"Our dedicated volunteers represent the values and principles of our organisation. We shall not tolerate any behaviour that brings the work of the RNLI and our people into disrepute."