Mubarak and Netanyahu at the White House last September wikimedia commons Hosni Mubarak and his former oil minister are being investigated for exporting artificially cheap gas to Israel and six European countries, according to Al Masr Al Youm.

Egypt's new authorities say these deals cost the country $170 million over the past five years. Chief prosecutor Magid Mahmud claims deals with Israel cost as much as $500 million, according to DEBKA.

Israel signed a 15-year contract worth 1 trillion cubic feet of natural gas in 2005, following up the big contract signed in 1979 after the Camp David Accords.

Gas exports from Egypt to Israel were supposed to resume this weekend, after being shut down since the pipeline was sabotaged in early February. That probably won't happen now. This represents a big worry for Israel, which relies on Egypt for nearly all of its gas supply.

Read about the world's 15 key strategic pipelines here >