Cisco Systems Inc. filed a case against three former top-ranking employees whom the company accused of stealing thousands of confidential information when they resigned to join a rival company.

Cisco claimed two internal technicians and a sales director had taken product designs, client lists and other confidential data to an unnamed rival in a complaint filed on November 18 at the District Court of Northern California.

Cisco said it had discovered evidence that two high-level technicians, Wilson Chung and James He, leaked thousands of confidential Cisco documents related to the development, production and pricing of their unreleased devices.

It also alleged that one of its former sales managers, Jedd Williams, used the trade secrets of Cisco to create a plan that he then recommended to the rival.

Chung reportedly spent weeks exfiltrating Cisco's classified hard drive resources, personal email, cloud storage, and the intranet of his new employer.

Chung, who had been employed at Cisco since 2007, claimed in November 2018 that his personal and work laptops had been stolen. As a result, a new Lenovo ThinkPad and Apple MacBook was given to him by the client.

Chung installed more than 3,000 Cisco documents and transferred data from the MacBook to his private iCloud account before leaving to work at the rival in February 2019, the filing said.

"These documents are confidential materials from Cisco and related, among other things, to Cisco's contributions to 5G technology and a pre-release video conference display prototype design specifications," Cisco said.

Cisco said Chung destroyed evidence to hide his actions when confronted with evidence of his misappropriation. He also performed internet searches such as "how to permanently erase icloud backup" and "how to see what the thumb drive is [sic] without detection," said the complaint.

Likewise, he is also charged with copying thousands of files to an external hard drive and "regularly taking photographs of Cisco's documents on his iPhone Max" before leaving to join the competitor.

He took a photograph of a quarterly report on May 13, 2019 showing the financial details of Cisco's third quarter sales, and category-by-category comparable income, the filing stated.

Cisco's former international joint marketing managing director, Williams, allegedly stole trade secrets linked to Cisco's revenue projections and prospects for business development, including spending commitments.

Williams reportedly backed up his Cisco computer on a home server after leaving Cisco, the filing claimed, and certain trade secrets stayed on that server.