Raleigh, N.C. — The State Board of Elections is investigating about $750,000 in questionable campaign contributions from a national political fundraising organization connected to former House Speaker Jim Black.

Black, who is in federal prison serving a sentence for accepting illegal contributions, was a finance director for the Democratic Legislative Campaign Committee (DLCC) for about four years. That raised concern among investigators for the Board, who found that Black had violated campaign finance laws.

"We followed every lead to ensure that we covered all the things that we knew about, as far as activity by Speaker Black," said Gary Bartlett, executive director of the Board of Elections.

Under state law, campaign contributions can only come from an individual. Contributions from a corporation or labor union are prohibited, Bartlett said.

"It is discouraging, and it's troubling, and it's something we need to take very, very seriously," said former Democratic political consultant Joe Sinsheimer, an activist who sparked the initial investigation into Black's affairs.

Sinsheimer also wants answers about a $30,000 contribution from the video poker industry, which had close ties with Black and the DLCC.

"When they do that, it's a way to basically have an unequal influence in our political process, and that's why we have to pay attention to this," Sinsheimer said.

The Board expects to wrap up its two-year investigation by the end of the year. It is also looking at three other national political fundraising groups to see if they violated North Carolina  campaign finance laws.

If the Board finds find anything illegal, the information will be turned over to the Wake County District Attorney's Office.

Black, 72, was sentenced in July to 64 months in federal prison and three years on probation for accepting more than $25,000 in cash from chiropractors while backing legislation favorable to the industry.

He was later found guilty on state bribery and obstruction of justice charges and sentenced to eight to 10 months, to be served concurrently with the federal sentence.

The state convictions stem from cash and blank campaign-donation checks that Black forwarded to former state Rep. Michael Decker in exchange for Decker's switching to the Democratic Party to help Black retain a share of the House speaker position.

Black later encouraged people to lie to authorities investigating his campaign finance activities, authorities said.

Decker, 62, was sentenced in April to four years in prison on one count of soliciting and accepting $50,000 in cash and campaign contributions.

He began serving his sentence in federal prison on Tuesday.