The 65-year-old suspect is one of two women caught on surveillance video leaving the victims' hotel room, Mexico City prosecutors said in a statement.
The statement said an autopsy on the two wrestlers, who were brothers, detected a substance found in eye drops that can damage the nervous system when mixed with alcohol.
One of the diminutive wrestlers went by the name "La Parkita" — or "Little Death" — and wore a skeleton costume in the ring. The other was known as "Espectrito Jr."
Prosecutors said previously that gangs of female robbers are experienced at using drugs to knock men out and rob them, but they may have used too strong a dose in this instance.
That may have been because of the wrestlers' small stature, although larger men have also died in similar crimes.
Police located the suspect by tracing calls from a cell phone belonging to one of the victims, the statement said. She was arrested Tuesday.
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