Stuart Campbell, a controversial blogger who runs the Wings over Scotland political website, has been arrested after a woman alleged she had been harassed online.

Campbell, 49, originally from Stirling, was arrested in Bath on Friday on suspicion of harassment and malicious communications, and released on bail until mid-September while police investigate further. The arrest was carried out by Avon and Somerset police at the request of the Metropolitan police.

The Herald newspaper reported that his arrest followed a complaint to police by a woman in her 30s living in south London. On the day of his arrest, Campbell tweeted: “For sucky reasons totally outwith my control (don’t ask), posts on Wings will be very sparse for an unknown period. Sorry, folks.”

In a statement, the Met said: “Police are investigating an allegation of online harassment. The allegation was made after a woman, aged in her 30s, attended a south London police station. The harassment is said to have taken place over the past two years.”

Campbell, who styles himself as the Rev Stuart Campbell, was asked for a comment but had not replied by the time of publication. In a post on his website, he said the allegations related to tweets which had not been deleted. He also claimed the tweets were not threatening in any way.

Although based in Bath since 1991, Campbell was the most prominent and active pro-independence blogger during the 2014 Scottish referendum campaign. He raised tens of thousands of pounds through crowdfunding campaigns to pay his salary and costs, and for other contributors to the Wings over Scotland blog.

He commissioned opinion polls, an advert on the Glasgow underground which attacked the media, and self-published the Wee Blue Book, a document he claimed set out the factual and economic case for independence.