US media group Cablevision has unearthed more than three years’ worth of accounting irregularities related to marketing expenses.

The bookkeeping errors have emerged at the group’s Rainbow Media cable-TV unit. A five-month internal inquiry revealed $6.2 million (€5.3m; £3.7m) of marketing payments that should have been entered in the 2003 accounts were instead brought forward to 2002, though the company corrected all but $1.7m before posting results. Rogue expenses “similar in size” were uncovered in the 2000 and 2001 accounts.

The investigation also discovered that false invoices had been used to build up reported costs.

It is not yet clear why employees sought to overstate expenses, though there is speculation that they may have been trying to make future earnings targets more reachable. Fourteen staff have been sacked at the AMC movie channel following the probe.

Data sourced from: Financial Times; additional content by WARC staff