When Lai bought an 88 per cent majority stake from former owner Jeremy Peace for £200m in 2016, he inherited a £3.7m loan the holding company owed the football club.
It has since been accruing interest and is now a debt of £4.7million.
Club accounts state there is ‘no fixed date for repayment’ and the loan is ‘payable on demand’. And there is no indication Lai does not intend to honour the debt.
However, a number of fans and some minor shareholders who own the remaining 12 per cent of the club are concerned the historical loan is yet to be repaid.
They believe the £4.7m could be useful for additions with the club struggling in the Premier League.
Although Lai inherited the loan and did not take it out in the first place, the holding company owned by his company, Yunyi Guokai Sports Development Limited, is now responsible for it.
It’s believed the loan, taken out when Peace was majority shareholder, was not repaid because it was accumulating interest at a rate advantageous to the club.
Lai has been reluctant to invest his own money into the club since spending £200m on his takeover in 2016.
Albion did, though, commit to spending in the region of £47million during the summer following their promotion to the Premier League.
Grady Diangana was signed from West Ham in a deal that could be with £18million, with Karlan Grant arriving from Huddersfield for £15million.
Matheus Pereira also saw his loan move from Sporting Lisbon turned into a permanent transfer for £8.25million.
The Baggies also bolstered their squad with the signings of Callum Robinson, David Button, Branislav Ivanovic and Cedric Kipre as well as the loan additions of Filip Krovinovic and Conor Gallagher.