Guernsey Police is investigating a leak to the BBC described by the force’s chief as “one of the most irresponsible I have ever come across”.
The investigation was launched after journalists from the corporation were apparently tipped off about officers, investigating four deaths on the island of Alderney (pictured, Reuters), raiding a medical practice.
The BBC was thanked by the police for not acting on "the leak with the same recklessness that was displayed by the person who provided it to them".
Asked whether it is cooperating with the police, or protecting its source, the BBC declined to comment.
Guernsey Police chief Patrick Rice said in a statement that there had been “much speculation in Alderney around the early on-scene arrival of BBC Guernsey [to the raid], with some suggesting Guernsey Police gave a pre-briefing about the operation”.
He said: “It is with regret, however, that I must confirm that someone did leak this information to BBC Guernsey. Whoever did so could have jeopardised a police investigation.
“As such we have launched an investigation in an attempt to identify the source of the leak.
“I did not take that decision lightly; however, this went far beyond your average leak of information. It was one of the most irresponsible I have ever come across and the source crossed a line when they put a significant police investigation at risk.“
He added: “I am grateful the BBC took its responsibilities seriously and did not act on the leak with the same recklessness that was displayed by the person who provided it to them.”
Press Gazette understands BBC journalists were present for the raid of Eagle Medical Practice on 2 April by ten police officers. Police said the raid followed the deaths of four patients which were of "concern". Although the BBC covered the raid, journalists did not apparently behave in a way that would have alerted anyone to the fact it was to be carried out.
Police leak investigations involving the media have come under increasing scrutiny in recent months after it emerged in September that the Metropolitan Police had secretly accessed the phone records of Sun journalists when investigating the Plebgate scandal.
Press Gazette subsequently revealed several other cases in which police forces have secretly accessed journalistic phone records, under the Regulation of Investigatory Powers Act, to obtain journalists' phone records and find sources.
Research by Press Gazette has also shown a sharp increase in media leak inquiries by police forces in recent years.
In October, it emerged that the Met Police investigated whether the source of its Cliff Richard leak – which led to the corporation covering a raid of his house live – had come from its Operation Yewtree.
A BBC spokesperson said: “In light of the ongoing police investigation we will not be commenting at this time.”