Two Whitby RNLI crew members have been "stood down" and three others have resigned following an investigation into "the production of inappropriate material of a sexual nature."
A petition has now been set-up calling for them to be reinstated, attracting hundreds of signatures to date.
The RNLI has been keen to stress that contrary to reports on social media, the matter "was not a trivial one."
A spokesman said: "Following an investigation at Whitby lifeboat station, two volunteers have been stood down. They have the right to challenge this decision and we are waiting to hear if they wish to do so. Three other people have resigned.
"We are restricted in what we can say, however we can confirm the investigation focussed on the production of inappropriate material of a sexual nature and associated social media activity directed at an RNLI staff member. We are aware of speculation about the issue on social media but we want to stress that this was not a trivial matter."
They added: "The lifeboat station should be an environment where people can expect to be treated with dignity and respect. We cannot allow bullying, harassment or discrimination in what should be a safe and inclusive environment and there will be serious consequences for anybody who demonstrates this behaviour within the RNLI.
"By challenging this behaviour, we are standing up for the thousands of volunteers who are committed to doing the right thing as they operate our 238 lifeboat stations, saving lives at sea around the clock, 365 days of the year. Our dedicated volunteers represent the values and principles of our organisation and we will not allow any behaviour that brings the work of the RNLI and our people into disrepute."
It follows the case in Scarborough last month when the long-serving RNLI coxswain Tom Clark MBE, was sacked.
Mr Clark was dismissed from his role after the RNLI said he had led an “unauthorised” training exercise.
More than 4,000 people signed a petition urging the charity to re-instate the decorated life-saver.
A bitter war of words broke out between the charity and supporters of Mr Clark.
The RNLI has also revealed that three other Scarborough volunteers left their roles within the charity.