a former chairman of the Humberside Police Authority has been arrested on suspicion of gross indecency and other offences.
Hull City Councillor Steven Bayes was detained in Northern Ireland on Monday but has since been released on bail.
The police in Belfast would only confirm that a 45-year-old man had been arrested.
Mr Bayes is hoping to become Labour's candidate for Hull East at the next election when John Prescott steps down.
Mr Bayes is a Labour member of Hull City Council representing the Orchard Park and Greenwood ward.
Although police in Northern Ireland would not confirm his arrest, a force spokesman said a 45-year old man who the BBC understands from other sources is Steven Bayes, was arrested by officers in Belfast at about 0900 GMT on Monday on suspicion of gross indecency and other offences.
Officers said the man had since been released on police bail pending further inquiries.