An ex-Intel employee accused of stealing $1 billion worth of trade secrets and using them to help rival AMD was indicted in Massachusetts Wednesday, according to news reports.

Biswamohan Pani, 33, of Worcester, Mass., was a design engineer at Intel's Hudson, Mass., offices before being hired away by AMD in June, according to the Worcester Telegram & Gazette. 

Pani is accused of accessing Intel's network remotely and downloading 13 top-secret documents and other proprietary information related to methods for designing microprocessors, "including a document explaining how the encrypted documents could be reviewed when not connected to Intel's computer system," the Telegram reports.

Prosecutors say AMD was not aware of Pani's alleged thefts and did not benefit from them, the Associated Press reported. Instead, prosecutors say Pani planned to use the secrets to advance his career at AMD. The information Pani allegedly downloaded "was worth more than $1 billion in research and development costs," the Associated Press reported. Pani told investigators he downloaded the top-secret documents to help his wife, who works for Intel, the Telegram reports.

If convicted, Pani could face decades in prison and large fines for stealing trade secrets and committing wire fraud. He was first charged in August in U.S. district court in Boston with stealing trade secrets. He was indicted Wednesday by a federal grand jury on four additional counts of wire fraud. He is free on $100,000 bail.

As the industry's two leading chip-makers, Intel and AMD have a longstanding rivalry. Both Intel  and AMD plan to announce new multi-core chips later this month. (Compare server products.)