Southend Council has questioned NHS bosses about allegations that staff are having sex with vulnerable mental health patients.

The claims against Essex Partnership University NHS Foundation Trust (EPUT) – which include allegations that staff supplied Class A drugs to patients on secure wards – were revealed by a BBC investigation on Tuesday night.

Alison Griffin, Southend Council’s chief executive, asked NHS executive officer Margaret Hathaway to update the health and wellbeing board on Wednesday night.

Ms Hathaway – chief finance officer for Southend, Castle Point and Rochford clinical commission groups (CCGs) – told the meeting the Radio 4 File on 4 programme had ‘raised some disturbing issues’.

She said: “We have taken measures as a result of this. EPUT has set up a helpline for anyone with concerns. All cases raised in the radio programme were already known. The CCGs will be working very, very closely with the chief executive of Essex Partnership University NHS foundation Trust.

“Actions will be taken as a result of this programme.”

CCGs are required to gain assurance that all serious incidents within the NHS are properly investigated and similar incidents don’t re-occurr.

Ms Hathaway said she did not know how many people had contacted the helpline since it was opened on Tuesday.

The BBC programme alleged that sexual abuse had occurred in both the south and north of the county.

Ms Griffin said she felt it was important to give assurances to the committee about what was being done.

The meeting’s chair, Conservative councillor Lesley Salter, for Belfairs ward, thanked Ms Hathaway for her update.

“We looking forward to hearing in the future that things are OK,” she said.

EPUT said it had investigated allegations, but did not specify which ones. The trust also said it was unable to immediately say whether previous allegations had been reported to police. A spokesman said checks were ongoing and a response would be made later

The spokesman added more generally: “We take concerns raised with us seriously and they are investigated as safeguarding incidents and reported to the police, if appropriate.”

Inspectors at the Care Quality Commission last inspected EPUT’s south Essex services in 2015 and rated them as good overall, but “safety” was rated as “requires improvement”.

Inspectors reported heavy reliance on agency staff, restrictive practice across the trust and safety at Basildon mental health unit that did not meet guidelines.

Patients and family members can call the helpline on 01268 739182.