The allegations, first reported in the Guardian, external, centre around the misuse of donations and of a “bullying culture” at the organisation, which has more than a hundred year-round volunteers and four paid members of staff.
Mr Joell-Deshields is accused of using vouchers donated by a sponsor to purchase luxury fragrances, as well as Apple speakers and headphones.
The BBC understands there are also accusations of a toxic culture at the organisation, including allegations made by a disabled volunteer, who said they received bullying WhatsApp messages from Mr Joell-Deshields.
Those with knowledge of the matter have told the BBC there is a separate ongoing legal dispute over allegations the organisation’s policies discriminate against disabled volunteers.
After the allegations emerged, a newly-formed board of directors for London LGBT Community Pride (LLCP), the community interest company which runs parts of the annual event, suspended Mr Joell-Deshields.
But in a statement, Mr Joell-Deshields appeared to suggest he did not recognise the new board’s authority to do so.
He said: “I remain in my role as CEO of Pride in London and as a director of London LGBT Community Pride CIC.
“The current legal and governance matters relate to the organisation itself. These matters are being addressed through the appropriate channels, and it would be inappropriate to litigate them in the press.
“Nothing in this statement should be interpreted as an admission of any allegation, nor does it comment on any other individual.”