The search is on for experts to inspect more than 2,000 installations operating under the controversial 'cash for ash' scheme.

The job, to be carried out on behalf of the Department for the Economy, went out to tender this week and the successful business will be guaranteed an eight-month contract to inspect 2,090 sites - with a possible extension of five years for potential 'enforcement' activity.

The programme of inspections, to include auditing as well as examination of boilers, is expected to take eight months, leading to a final report by the end of November, a spokesperson said. An advertisement placed in the EU Journal said the purpose of the programme was to assess "compliance" with regulations.

Where non-compliance is identified, the successful applicant will be expected to recommend action "including enforcement." In some cases, this may involve permanent exclusion from the scheme.

The optional extension periods provide flexibility for the contractor to support the Department for the Economy during the enforcement process.

Inspectors will also be expected to provide analysis and trend information, findings, conclusions and recommendations for future action to the Department for the Economy.

Energy watchdog Ofgem said in January it had inspected just 63 installations.

Of those, payments had been suspended on 33 for a number of reasons including technical issues.

The Renewable Heat Initiative scheme was set up in 2012 while former First Minister Arlene Foster was Minister for Enterprise.

The Northern Ireland programme failed to cap payments as the UK scheme had done, making it possible for businesses to make money by burning fuel

In the first 34 months of the scheme, 923 applications were made. A spike of 881 came after flaws were identified before the scheme was brought under control in November 2015.

The total RHI spend in Northern Ireland is estimated at over £1billion over the next 20 years, landing Stormont with a £490m bill.

Former Deputy First Minister Martin McGuinness resigned after DUP leader Arlene Foster refused to step aside while the RHI scheme was investigated, triggering the collapse of Stormont.

A spokesperson said: "The Department wants to ensure openness and transparency around the RHI scheme and will consider publishing the findings following receipt of the final report."

Belfast Telegraph