"We sat down and talked about it and realised we had three options - either she took redundancy, managed a new team for the organisation or moved to Germany and I commuted.
"I decided I could fly in from Frankfurt at the beginning of my week, find some digs and then fly back at the end of the week.
"I told my boss we were planning to move to Germany and said 'I don't come to you with a problem unless I have a solution'.
"He asked me what my solution was and I told him I was going to commute.
"He looked at me blankly at first but it didn't take us long to sort it out.
"The force has been extremely supportive and arranged my hours so it suits me, the force and the community.
"So far, it's been a workable solution but people still think it's extraordinary. The only reason things might change would be if Annie finds it too difficult."
Inspector Rich Ward, Pc Hannigan's boss, said: "I've certainly never known anyone travel this kind of distance to get to work but Sean is the sort of character who will make this work.
"The alternative would have been to lose a great police officer. Sean is an absolutely tremendous police officer and his commitment and enthusiasm are second to none."
Derek Crane, chairman of Barlestone Parish Council, one of the villages on Pc Hannigan's beat, said: "I don't know how he does it but we are very glad we have been able to keep him because he is such a good and dedicated police officer."
Ivan Stafford, chairman of Leicestershire Police Federation, which represents rank and file officers, said: "It's an extremely rare situation and it shows his dedication to his job.
"The only case similar I can think of is an officer who was based at the airport and lived in Spain.
"Anecdotally, you hear about officers in the south who live in northern France, but it's very uncommon."