A mysterious low-pitched humming sound has been troubling some Wellington residents for the last few days and it seems no-one has any idea what it might be.

The Wellington City Council has had several calls over the past few days with the most recent being about 5am today.

Spokesman Richard MacLean said the complaints had been coming in from Mt Victoria, Newtown and Mt Cook residents. "We are interested to hear if this starts to become a constant thing. We are keeping our ear to the ground."

One Mt Victoria resident said he and his fiancee had noticed the noise on Saturday and it hadn't stopped since.

He likened it to a low to medium pitched humming sound and said it went all day and all night and was "doing his head in".

The phenomena has also been reported in various parts of the world, including Auckland's North Shore.