Health watchdogs and an NHS trust have launched investigations into the death of a frail pensioner just hours after an out-of-hours doctor was allegedly "too drunk" to operate her oxygen supply.

Agnes Seecoomar claims the doctor, who has not been named, arrived at her mother Dorothy's flat, in Dover House Road, Putney, "incoherent and slurring his words" on August 15 this year.

She alleged he turned up with bloodshot eyes, appeared to be under the influence of alcohol or drugs and failed to understand a St George's Hospital registrar's simple instructions during a subsequent phone conversation.

Her mother had been recovering at home from a serious chest infection and was on an oxygen supply when she called for an out-of-hours doctor.

The 81-year-old was admitted to hospital the next day but died just 24 hours later on August 17 prompting both her daughter and the registrar to launch a complaint.

Harmoni, the largest private provider of urgent care services in England, employed the doctor and spent two months investigating the incident.

The company dismissed the doctor last week but found no indication of alcohol or drug abuse.

Ms Seecoomar, a teacher from West London, said her mother had suffered unnecessary distress.

She said: "Any competent doctor would have seen she was not getting enough oxygen.

"I told the registrar I was frightened as the doctor attending my mother appeared incapable of doing his job, was rambling, sweating profusely now and his eyes were bloodshot.

"The registrar told me he would report him straight away.

"People think we still have an NHS - but we don't, we have commissioners and providers.

"It seems to be a competition to see who can provide healthcare at the lowest possible cost."

NHS South West London, who contracted Harmoni for out-of-hours care, and the General Medical Council, the body which licenses doctors, have both opened inquiries.

The Care Quality Commission, the healthcare watchdog, is also examining the case.

A spokesperson for Harmoni said: "We have contacted Ms Seecoomar and did invite her to meet with us.

"Ms Seecoomar declined this invitation so we have sent her our findings in writing which include confirmation that the doctor no longer works for Harmoni.

"There is no evidence at all to support any suggestion or allegation that this doctor was intoxicated whilst on duty."