U.S. intelligence services warned Germany that a Chinese takeover of German semiconductor manufacturing equipment maker Aixtron could give Beijing access to technology for military purposes, reported German paper Handelsblatt on Wednesday.

The German economy ministry announced Monday it had removed its approval for Fujian Grand Chip Investment Fund (FGC) to acquire Aixtron for EUR 670 million (US $732 million), due to unspecified national security concerns.

Handelsblatt cited German intelligence officers familiar with the matter in its report, but the economy ministry declined to comment on the claims, saying it could not give any details about the “origin of the nature” of the information about why the acquisition clearance was withdrawn.

A German Economic Ministry spokeswoman added the review of the deal could take between two to three months before the ministry was able to collect relevant documentation.

Aixtron stated it had not received any questions from the ministry related to the review.

Following the latest development, Aixtron shares dropped 7.3% to trade at a five-month low of EUR 4.79 (US $5.23) by 1011 ET, below the EUR 6 per share that Chinese investor FGC had offered shareholders for the stock.

The Handelsblatt report cited German intelligence sources, said U.S. authorities had showed representatives of German ministries evidence last Friday, at a meeting at the U.S. embassy in Berlin. However, the U.S. authorities did not hand over the relevant evidence over.