Russian investigators opened a new corruption case Wednesday against subcontractors building a space center where workers have gone unpaid for months and have appealed directly to President Vladimir Putin for help.

The Vostochny Cosmodrome, under construction in a remote area in the Far East, is a priority project that will give Russia its own facility for manned space launches and ease its reliance on the Baikonur Cosmodrome in Kazakhstan.

The Interior Ministry on Wednesday said its investigators had uncovered the embezzlement of 50.5 million rubles (nearly $1 million) by one of the subcontractors, in addition to the embezzlement of 48 million rubles by a separate subcontractor uncovered earlier. The ministry did not name the subcontractors.

Some of the construction workers have not been paid since December, and they have staged several hunger strikes.

To draw attention to their plight, they painted a message to Putin on the roofs of their barracks in huge white letters that said: "Dear Putin, V.V. Save the workers. We want to work." Photographs taken from a helicopter were posted on the Internet.

The workers also were invited to make their case to Putin by video link during his tightly scripted call-in show last week, and the president promised they would receive their overdue wages.

Even so, about 20 workers declared a new hunger strike on Wednesday. In a statement reported by the Interfax news agency, they said their employer, a subcontractor called Stroiindustriya, owed 311 workers a total of 16.1 million rubles (about $310,000).

As Russia's economy has slipped into recession this year as a result of low oil prices and sanctions imposed by the West, some companies have struggled to meet payrolls. Major Russian companies are under government pressure not to lay off workers, so as a result wage arrears are on the rise.

Strikes and protests have broken out around the country, but as at the cosmodrome they have been small and directed at companies or local governments. The anger has not been directed at Putin, who most Russians still see as the solution to their problems and not the cause. His approval ratings remain over 80 percent.

Putin, however, appears well aware of the potential threat the economic difficulties pose to his hold on power. He spent most of his four-hour call-in show reassuring Russians that his government was coping with the economic challenges and that the worst was over.