The Kernel startup news blog could be forced by an employment tribunal to pay out up to £11,000 over its failure to pay a former contributor money they are owed.

The financial problems faced by the Kernel first surfaced in September 2012, when MediaGuardian reported that a number of former contributors were owed thousands of pounds.

One, Jason Hesse, who worked at the Kernel between March and May 2012, subsequently won a summary judgment from an employment tribunal hearing when Sentinel Media, the company that owns The Kernel, and for which co-founder Milo Yiannopoulos is the sole remaining director, failed to present a defence.

Hesse tweeted on 27 December: "It's been 8 months that I've waited to be paid by The Kernel (still not received a penny). Looking forward to the judge's award in 2 weeks!" He added that the tribunal decision on what amount Sentinel Media should pay, due on 15 January, "will hopefully put an end to this farce".

Hesse has claimed payments totalling more than £11,600 plus interest – including £6,500 in unpaid wages, £1,615 for constructive unfair dismissal, and £184 to cover the hosting costs for the Kernel's website.

The Kernel, which covers the London startup scene, has just reached its first birthday but is still facing payment demands from people who have written for it but not been paid.

Yiannopoulos has claimed to be putting substantial funds into the business. In September he wrote in a blog post on the Kernel that "£30,000 (my personal investment into this business) doesn't get you very far in media".

In December, in an interview with a blogger writing for the Forbes website, Yiannopoulos claimed to have spent £50,000 of his own money since the Kernel was set up. He also claimed in the interview to have spent "twice as much money on lawyers as on editorial".

Some contributors received part-payments of the amounts owed at the end of October amounting to a couple of thousand pounds, but nothing further, despite promises from Yiannopoulos that he would continue the repayments on a monthly basis.

In emails seen by MediaGuardian, Yiannopoulos threatened to publish what he claimed were embarrassing details and photographs of one contributor who sought repayment, and said "I can't ignore the fact that the majority of damage to The Kernel can be traced back to you and your childish, capricious behaviour".

The contributor, who asked not to be named, told MediaGuardian they had referred the emails to the police. They are also considering taking legal action against The Kernel over the unpaid money.

A spokesperson for Sentinel Media said: "We find the Guardian's obsessive fascination with our finances comically absurd. Needless to say, we would not comment on private financial matters. The Kernel continues to enjoy healthy growth in both readership and revenues, as evidenced by our recent expansion into the German market.

"We look forward to augmenting our vibrant and growing stable of writers with a move into Miami, Florida, later this year, from which we will report on emerging markets in Central and South America for the benefit of our flourishing community of European and American readers."

• This article was amended on 9 January 2013 as it wrongly referred to industrial tribunals. Since 1998 these have been called employment tribunals.

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