The Serious Fraud Office (SFO) has released an update on its investigation into property developer the Signature Group.
Last week the agency announced it had raided three residences in Merseyside and Greater Manchester in connection with a suspected £140m fraud involving 1,000 investors linked to the company.
Four people arrested on 21 February have now been released pending further investigation.
Signature Group, known as Signature Living, operated for more than seven years, and turned historic UK buildings into luxury hotels, apartments and offices.
Its developments included the Coal Exchange hotel in Cardiff (pictured), the Shankly and Dixie Dean football-themed hotels in Liverpool, and the George Best hotel in Belfast, which never opened.
Investors loaned money to Signature Group or purchased hotel rooms in its properties and were promised between an 8% and 15% return on their investment.
However, the business collapsed into administration in 2020 with losses of up to £140m.
Bedroom investors were owed around £1.3m from the Shankly hotel alone when it fell into administration, according to documents filed with Companies House.
SFO director Nick Ephgrave QPM said well-known local landmarks had been used to “lure investors” to the scheme.
"We have people up and down the country left out of pocket, and buildings left derelict at the centre of our cities,” he added.
The investigation continues.