Norwich — Norwich Public Utilities General Manager John Bilda, a central figure in the controversy over trips to the Kentucky Derby, is on medical leave and is not expected to return until after the holidays, an NPU official confirmed Monday.

While he is away, NPU is being managed by the leadership team of Assistant General Manager Chris LaRose and Division Managers Steve Sinko, Jeff Brining and Kerri Kemp, NPU spokesman Chris Riley said Monday. Riley said he could not comment on Bilda's situation.

Bilda was one of four NPU officials, including Sinko, found in violation of the city's ethics code for attending controversial trips to the Kentucky Derby, which were hosted by the Connecticut Municipal Electric Energy Cooperative. Bilda, his spouse and other family members attended the Derby trips in each of the four years CMEEC held them. In September, he publicly apologized and made a $15,000 donation — the estimated value of the 2016 trip for him and his wife — to a fuel assistance fund.

The trips included no official business and cost a combined total of $1.02 million for four years. Bilda had been vice chairman of the CMEEC Board of Directors until November, when he was named chairman of the cooperative’s risk management committee.

Public outcry over the Derby trips led to changes to the cooperative’s policies and in a new state law, which called for more oversight of CMEEC operations.