The Irish Cancer Society has raised serious concerns over the number of people waiting more than three months for a colonoscopy.

The society said that at the end of November, 3,510 public patients were waiting longer than three months for the test used to detect cancer.

This marks an increase of 954 people since November 2014 and also follows a rise to a peak of 4,235 people waiting in October this year.

The society said the waiting times are unacceptable and serve to highlight the gap between public and private patients, who can get the test done within 12 days.

The HSE's targets state that no one should wait more than 13 weeks for a colonoscopy.

The figures for November 2015 show an overall drop of 725 in the past month, which the Irish Cancer Society said is encouraging but not enough.

HSE Deputy National Director of acute hospitals Angela Fitzgerald has said she expects a 13-week wait period for a colonoscopy for routine patients will be reached in the first quarter of next year.

She told RTÉ's News At One that the HSE has a waiting time of four weeks for patients who are deemed urgent.

Ms Fitzgerald said in the last two months there has been a 16% reduction in the numbers waiting and the HSE, by the end of the year, will make sure there is no patient is waiting more than 12 months. 

She said the private sector is being used to give immediate capacity and a clinical lead is being appointed.