The Fundraising Regulator is investigating allegations that collectors for a major children’s charity tried to pressure people into donating.

Great Ormond Street Hospital (Gosh) Charity said it is “deeply concerned” by the allegations, following a Times investigation, and “does not condone any fundraising practices and behaviours that do not comply with high standards we expect”.

The newspaper said an undercover reporter had trained as a fundraiser at a third-party marketing company, IBA Global, to sign people up as donors to the charity.

The Times said that IBA Global fundraisers were instructed to “never give” customers an option on the door and take them on an “emotional rollercoaster”, as well as being taught to influence people and create the impression others in their community had already donated.

Fundraisers signed an agreement saying they would earn “commission” for each customer signed up, the newspaper said, and it gave an example of one woman having had to turn a fundraiser down at least four times when approached on her doorstep for the charity.

The regulator’s Code of Fundraising Practice says: “While reasonable persuasion is allowed, you must not fundraise in a way which is an unreasonable intrusion on a person’s privacy, is unreasonably persistent or places undue pressure on a person to donate.”

A spokesman for Gosh Charity said they are “taking this matter extremely seriously and immediately suspended working with IBA Global”.

They added: “We work extensively with agencies to train and support their fundraising staff and require that they fully comply with the Code of Fundraising Practice.

“We are now conducting a full independent, external investigation and will take further appropriate action if any breaches are found.

“Door-to-door fundraising is one of the most effective ways for us to raise much-needed money and engage with people.

“Without the generosity of our supporters, we simply couldn’t transform the lives of seriously ill children at the hospital now and in the future.”

The Fundraising Regulator said it is “concerned” and “disappointed” by what it has seen but said Gosh had “followed the right procedure and self-reported to us”.

They added: “We can confirm that we have opened an investigation and will be working with the Charity Commission for England and Wales.”

The regulator said charities must ensure that reasonable persuasion “does not cross the line into undue pressure or unreasonably persistent behaviour”.

It said face-to-face fundraising methods “can be very effective” but that charities “must take care to ensure that their fundraisers and those that fundraise on their behalf are operating in line with the Code, and that they have appropriate oversight and training”.

The regulator opened a market inquiry in October into the use of subcontractors by fundraising agencies and said it expects to publish the findings “in the next few weeks”.

It added: “We would advise the public that they always have the right to end a conversation with a fundraiser.

“Good fundraisers will be happy to end the interaction and will not pressure you to keep talking. You can always donate later if you are sympathetic to a charity’s cause.”

A Charity Commission spokeswoman said it is “assessing information shared with us by the Times” and that the Gosh Charity had reported the newspaper’s findings to the commission “as a serious incident”.

She added: “We are assessing the matter to determine what, if any, role there might be for the Commission. We are working with the Fundraising Regulator to determine any next steps.”

IBA Global said in a statement: “Pressurised fundraising is not permitted, IBA Global operates a policy of reasonable persuasion only, as per the FCOP and training/guidance.

“Complaint management, compliance and auditing processes are in place for both the agency and fundraisers in line with the requirements of the Fundraising Regulator.

“If a fundraiser is unable to meet the standards required, their contract would be terminated. We will, of course, co-operate with any requests from the Fundraising Regulator.”