MADRID- Police searched the Seville headquarters of Spanish engineering and energy group Abengoa SA on Tuesday as part of an investigation led by high court prosecutors, the Guardia Civil force said.

A Guardia Civil spokesman said no arrests were made during the search, which comes in the middle of a bidding war for the holding company of Abengoa SA which voluntarily entered bankruptcy proceedings in February. 

Abengoa declined to comment.

A judicial source said the search related to a legal complaint brought by a group of shareholders in 2016 over alleged investor fraud and falsification of documents during previous financial troubles.

As part of the investigation, a high court judge requested various documents from Abengoa, as well as audit firms KPMG and Deloitte, the sources said.

KPMG and Deloitte were not immediately available for comment.

Last week a group of foreign investors and retail shareholders made a non-binding takeover bid worth 200 million euros ($238 million) for a 70% stake in Abenewco1, the holding company which owns most of Abengoa's assets.

Their bid gatecrashed an earlier non-binding offer from a group of investors led by Los Angeles-based private equity fund TerraMar Capital LLC. That offer was also worth 200 million euros and aims to control 70% of the company. It included a 50 million euro capital increase.

In 2016 Abengoa narrowly avoided becoming Spain's largest corporate bankruptcy after striking a deal to refinance 9 billion euros ($10.71 billion) of debt, handing control of the company to an assortment of banks and investment funds.

The deal failed to solve the company's woes and by the end of 2019, the most recent period for which complete figures are available, Abengoa posted a 549 million euro loss, while its total debt stood at 5.95 billion euros.

A proposed restructuring to tackle the debt mountain unravelled in February, prompting the bankruptcy proceedings.

($1 = 0.8402 euros)

(Reporting by Nathan Allen; editing by Jesus Aguado; editing by Jason Neely) ((n.allen@thomsonreuters.com; +34 617 792 131;))