An NHS helpline has been set up for patients of a Scots breast cancer surgeon who is facing separate investigations into his treatment of almost 100 women by the police and the General Medical Council.

Lawyers acting for his former patients allege Glasgow-born Ian Paterson, who worked in the West Midlands, carried out "unnecessary, inappropriate or unregulated" operations while employed by the NHS and private hospitals.

Mr Paterson, who has pledged to fully co-operate with the GMC inquiry, undertook the majority of his work at Solihull Hospital after being taken on by the Heart of England NHS Foundation Trust in 1998.

In a statement, a trust spokesman said it was alerted to concerns surrounding Mr Paterson's practices in 2007 and had instigated a detailed review of breast surgery services provided through Solihull Hospital.

The spokesman added: "This review - identified that a surgical technique for mastectomies used by one of its consultants, Mr Ian Paterson, required closer scrutiny to establish whether it represented best practice.

"An external review highlighted that this was not a usual procedure and that Mr Paterson had not followed guidelines to introduce a new technique.

"This trust's position, after careful consideration, was that the technique was not an approach considered appropriate going forward, and the method was therefore stopped."

Following the inquiry, the trust began a process of identifying patients who may have undergone the procedure to review their current clinical condition.

Mr Paterson was suspended by the GMC last month and was "excluded" from the trust in 2011 due to ongoing concerns among officials, who extended the recall to include all patients who had undergone a mastectomy.

The process of recalling more than 550 patients was completed by March this year.

Dr Aresh Anwar, medical director for Solihull Hospital, said: "We have invited all of Mr Paterson's patients who underwent a mastectomy to see an alternative surgeon for a review of their treatment and care. This programme is now complete.

"We are keen to hear from any patient who may have concerns or further questions and have set up a helpline to ensure that these can be addressed quickly."

Thompsons Solicitors, which is pursuing negligence claims on behalf of patients, said Mr Paterson worked at a number of NHS and private hospitals from 1994.

An investigation into Mr Paterson by the GMC potentially spans up to 700 cases of a procedure that involved leaving some breast tissue behind after a mastectomy, Thompsons said.

It is also alleged that up to 450 women could have had invasive breast surgery when a biopsy might have been sufficient.

In a statement confirming the police inquiry into Mr Paterson, who has not been arrested, Detective Chief Inspector Matt Markham said: "West Midlands Police can confirm it has received a referral from the General Medical Council in relation to allegations about the medical practices of a surgeon who previously worked in Solihull. A criminal inquiry has been launched."

Kashmir Uppal, a senior medical negligence solicitor at Thompsons, said she believed patients had been subjected to needless worry and risk.

Ms Uppal added: "The women who have come forward so far have been very brave. Hopefully, all who have had unnecessary or inappropriate treatment will seek reassurance or justice."

Mr Paterson's registration with the GMC was suspended after an Interim Orders Panel meeting on October 29. A GMC spokesman said: "This means the doctor cannot work as we investigate concerns about his fitness to practise."

In a statement issued on behalf of Mr Paterson, the Medical Defence Union (MDU) said he was co-operating fully with the GMC investigation. A MDU spokeswoman said: "He cannot comment further due to his duty of patient confidentiality and the ongoing investigation."